The present invention relates to a technology for forming a moving picture obtained by photographing an object with a virtual camera, and displaying the moving picture on a display screen of a display device. The object moves in a virtual three dimensional field in accordance with manipulation contents conducted by a user, the manipulation contents being accepted via a controller.
Entertainment apparatuses such as a TV game machine, which is capable of performing a flight simulation and a drive simulation by the use of a three dimensional graphic animation, have been recently spread.
In this kind of entertainment apparatuses, a player controls an object representing an airplane, an automobile and the like by the use of a controller connected to the entertainment apparatus, and can allow the object to move in a virtual three dimensional field. This entertainment apparatus generates a moving picture obtained by photographing the object moving in this three dimensional field by the use of a virtual camera, and displays the moving picture on a display screen of a display device connected thereto.
Incidentally, in the conventional entertainment apparatus capable of performing the flight simulation and the drive simulation, the virtual camera is set at a position determined uniquely (fixedly) depending on a positional relation between the camera and the object.
FIGS. 15A and 15B are drawings for explaining a positional relation between an object (an object representing an airplane) 901 and a virtual camera 902 in this kind of conventional entertainment apparatus. Hereupon, FIG. 15A shows a state where the object 901 and the virtual camera 902, which are disposed in a three dimensional field, are overlooked just from above, that is, from an infinitely long distance of the Z-axis, and FIG. 15B shows a state where the object 901 and the virtual camera 902, which are disposed in the three dimensional field, are viewed just from the side, that is from an infinitely long distance of the X-axis. Note that illustrations of map constituent elements disposed in the three dimensional field are omitted in these drawings.
As illustrated in FIGS. 15A and 15B, in the conventional entertainment apparatus capable of performing the flight simulation and the drive simulation, the virtual camera 902 is set at a camera setup point A, that is, a position higher by a predetermined distance H than a position to the rear of the object 901 by a predetermined distance L. The camera setup point A is disposed above a line 903 passing through the object 901 along the moving direction of the object 901. Alternatively, the virtual camera 902 is set at a camera setup point B, that is, a position of the object 901. A sight line of the virtual camera 902 is settled so as to be pointed at an arbitrary point on the line 903 further in front of the object 901.
FIGS. 16A and 16B are schematic views showing a pictorial image obtained by photographing the object 901 by the use of the virtual camera 902, which is disposed as illustrated in FIGS. 15A and 15B. Here, FIG. 16A shows an example of the pictorial image obtained by the virtual camera 902 when the virtual camera 902 is set at the camera setup point A in FIGS. 15A and 15B, and FIG. 16B shows an example of the pictorial image obtained by the virtual camera 902 when this camera 902 is set at the cameral setup point B in FIGS. 15A and 15B.